Protester: 'Killing Muslims on Ashura Is Like Crucifying Christians on Christmas.'

The Iranian government's deadly crackdown on demonstrators Sunday, when security forces fired on protesters on the Muslim holy day of Ashura -- a day on which violence of any kind is forbidden -- has raised anti-government anger to fever pitch.

"Killing Muslims on Ashura," one protester told ABC News by telephone from Tehran today, "is like crucifying Christians on Christmas."